The present invention is directed to a liquid transfer material formed of an apertured, necked laminate for use, for instance, as a liner in a disposable personal care absorbent article and a process for making the laminate. The necked laminate is formed from sheet layers of at least one non-elastic neckable material laminated to at least one non-elastic film layer. The laminate is apertured and is extensible and retractable in at least one dimension. This laminate extensibility and retractability is the result of striated rugosities in, for instance, the longitudinal dimension of the film layer which enables the necked laminate to have an amount of extensibility and retractability in the transverse dimension.
Materials that are highly permeable to aqueous liquids are used for top liners, surge layers, and other liquid transfer devices in a wide variety of personal care absorbent articles such as diapers, training pants, incontinence garments, mattress pads, wipers, feminine care products (e.g. sanitary napkins), and in medical applications such as medical drapes, wound dressings and wraps, and the like.
These laminates are made such that the article can be produced with relatively low cost and are thus disposable after only one or a few uses. Much research and development continues, however, to achieve xe2x80x9ccloth-likexe2x80x9d visual and tactile qualities in these articles without sacrificing breathability and low cost, while also providing an article that generally allows liquid to flow in only one direction. One disadvantage of such articles is that the combination of elements used to make the article does not xe2x80x9cgivexe2x80x9d like, for instance, a fabric made from cotton, which due to its fiber and yarn structure, has a natural ability to extend and retract. These properties are necessary to allow the article to conform to the user""body, thereby feeling and appearing to be more xe2x80x9ccloth-likexe2x80x9d. One known solution to this problem has been to incorporate elastomeric or elastic materials into the article. Unfortunately, incorporation of such materials generally results in increased costs due to more expensive material components. If breathability is attained by stretching a filled film to form micropores, there are problems associated with maintaining breathability of filled elastic films since the recovery of the elastic material after stretching generally closes or partially closes the micropores which had been created for breathability.
Heretofore, to provide laminates with transverse extensibility and retractability, nonwoven web layers were necked (as defined below) prior to applying an elastomeric sheet made using an elastomeric polymer as described in, for instance, commonly assigned U.S. Pat. No. 5,336,545 to Morman. Necking of the nonwoven web allowed it to extend in the transverse direction. Without the elastic sheet attached to the nonwoven web, however, the laminate would not have significant recovery or recovery force after the extension.
The present invention avoids these and other difficulties by providing an inexpensive, liquid transfer material formed from a necked laminate which achieves transverse extensibility and retractability using non-elastic materials.
The present invention is directed to a liquid transfer material formed from a necked laminate and a process for making the laminate. The necked laminate is formed from sheet layers of at least one non-elastic neckable material laminated to at least the non-elastic film defining a longitudinal and transverse dimension. At least the film layer of the laminate is apertured in an area where liquid transfer through the laminate is desired. The entire laminate may also be apertured. The non-apertured part of the laminate remains extensible and retractable in at least one dimension without significantly reducing the breathability and/or liquid barrier properties of the film layer. This laminate extensibility and retractability is the result of striated rugosities in, for instance, the longitudinal dimension of the film layer which enables the necked laminate to have an amount of extensibility and retractability in the transverse dimension. A breathable laminate may be made by first partially stretching the non-elastic film layer, attaching a non-elastic neckable layer to form a laminate and then stretching the laminate to neck the laminate and lengthen the film to its desired fully stretched configuration.